GPS tracking is one of the most convenient answers to questions of location in movies. How did you locate the stolen shipment of cars? Where did the kidnappers take their hostage? These questions and more are often magically solved by a single, simple solution: GPS tracking devices.

Of course, as per usual, Hollywood is over-exaggerating a bit when it comes to the capabilities and convenience of GPS tracking in movies. In fact, the explanation movies often give for GPS tracking is completely inaccurate! Here are a few myths that movies tend to capitalize on and what the truth behind them actually is:

Myth: A GPS tracking device gives off a signal that can be tracked.

This is actually backwards! Most GPS tracking units are actually receivers, meaning they can’t be activated to create a signal! In movies, GPS is commonly “being tracked” as if it’s giving off a signal, while in fact it’s merely receiving one.

Myth: You can “ping” a GPS unit to find its exact position.

A GPS unit has a single function, which is to determine its own position in space. This means that it can’t be “pinged” by a central controller. In reality, a GPS unit needs to be paired with a transmitter to do this. Remember, a GPS unit is a receiver!

Myth: A cell phone’s GPS can be remotely activated to retrieve its position.

Technically, this is possible, although not in the way the movies portray it. First, position transmission must be enabled from the phone itself—it can’t be done remotely unless it’s paired with another device. Second, “line of sight” to a carrier satellite must be open—meaning a person can’t be under a bridge or underground. Finally, the location is generally an approximation due to cell tower triangulation.

Myth: You can track the recent movement history of a device via GPS.

As mentioned above, GPS units are only programmed to display their own current location in space. This means that they don’t have accessible history! Modern car GPS systems or smartphones have history because they’re connected to hard drives and programmed to cache data for users. Commercial GPS is purely for real-time locating, however.

Myth: GPS units are the size of pennies and can be hidden anywhere.

Again, this is technically true in some cases, but not as it’s shown in the movies. Micro GPS receivers are often used in conjunction with larger hardware and are made small to be a space-saving mechanism. Effective GPS units are usually about the size of a smartphone in reality.

The next time you’re watching an action flick or a nail-biting drama and GPS technology enters the picture, ask yourself if it’s being sensationalized. Hollywood loves to stretch the limits of technology to tell a story, and GPS technology is no exception.

In reality, GPS technology is actually very amazing and has innumerable practical applications. But you’re more likely to see GPS tracking devices used to help determine global fleet positions than you are seeing it lead an action hero to the bad guys.